[GSBN] building in Haiti

Tue Mar 1 21:07:54 UTC 2011

Hi Bruce - you set a challenge

The only security I can think of to prevent de-lamination is doing you best to ensure that the earth will stay pretty dry, and left with a well keyed and very fibrous surface that will tie the lime to it. 

One Japanese technique I have heard of, but not tried, to ensure that earthen plaster layers  do not delaminate in earthquakes looks very time consuming.  It involves tying short lengths of rope or string (baling twine?)  into the structure  at frequent intervals all over the wall, and then progressively pulling these through each layer of plaster as they are laid up. Can't see why it would not work using LoE.  Might be worth a trial as a mechanical way of holding plaster layers in place.

PS Some engineers and I are venturing into the NZ earthquake zone in a couple of weeks to see how earthen and strawbale building have performed - very few reposts have come out yet, as the major efforts are still on search and rescue, and survival for those in the worst hit areas.

Graeme
Graeme North Architects
49 Matthew Road
RD1
Warkworth
tel/fax +64 (0)9 4259305

graeme at ecodesign.co.nz
www.ecodesign.co.nz

On 2/03/2011, at 9:11 AM, Bruce King wrote:

> 
> Hi, folks, we've got a bit of a debate going as to what constitutes a security barrier, which is fine by me, but I for one would really like to hear more about lime plasters over earth.
> 
> Answers so far, as well as my experience, suggest that LoE (lime over earth) systems work very well if, and only if, you have a familiar and consistent mix of lime, clay, straw, etc.  All of the ingredients are finicky (you can't just substitute one lime for another, or one clay for another), all depend on careful workmanship (application, curing, scratching, etc.), none are for newbies.
> 
> In Haiti, though we will have one or two pros running things (maybe some of y'all), we will be working with a Haitian crew of unknown skill, using clay, sand and lime whose properties and behavior are unknown.
> 
> Are we crazy to even contemplate a LoE system?  Remember, this will be a very public house seen and scrutinized by a lot of people and organizations.  There's no room for screwups or excuses.  If it cracks, or delaminates, or in some other way fails, the whole project looks bad.
> 
> We'd rather look good.  Any further advice would be much appreciated.
> 
> PS to Graeme North:  thanks for the tips, I know that cintoflex is good stuff, and may even be available in Haiti.  And prayers for New Zealand, you guys got hit hard.  Prayers for Haiti, too;  a year after their earthquake, the city and country still look like it happened a week ago, there's that little recovery.  Poverty, dysfunctional government, and a lack of infrastructure is a fairly deadly combination that even the most noble and intelligent people (as are Haitians) can barely overcome.
> 
> Thanks,
> 
> Bruce King, PE
> Director of EBNet
> Ecological Building Network
> the art and science of building well
> bruce at ecobuildnetwork.org 
> PO Box 6397
> San Rafael, CA 94903 USA
> (415) 987-7271
> follow us on Twitter: @EBNetwork
> 
> On Mar 1, 2011, at 11:43 AM, Andy Horn wrote:
> 
>> Hi Martin
>> I agree it is more about securing the windows and doors.
>>  
>> Plaster aside, for anyone who has not yet tried – but getting through a wall of straw is no mean feat.
>>  
>> I once got called in to look at saving storm wrecked load bearing SB after the guys building had left for a long weekend without covering up ……so I helped with cutting out chunks of un-plastered wall, so as to retrofit in sets of load bearing timber posts. Armed with a chainsaw you would be surprised at just how difficult it was.
>>  
>>  
>> Andy Horn
>>  
>>  
>>  
>>  
>> From: GSBN-bounces at greenbuilder.com [mailto:GSBN-bounces at greenbuilder.com] On Behalf Of martin hammer
>> Sent: 01 March 2011 05:54 AM
>> To: (private, with public archives) Global Straw Building Network
>> Subject: Re: [GSBN] building in Haiti
>>  
>> Bruce, all,
>> 
>> Although on the EBNet Haiti team (in addition to the BWB SB Haiti team), I'll jump into the GSBN forum with a couple thoughts on the plaster and the security issue.
>> 
>> The security concern will be greater in some locations than others.  Generally, the more urban the greater the concern.  It seems obvious that both in perception and as a physical obstacle, mesh reinforced cement plaster would be the most secure plaster, and I’ll say probably secure enough.  (Notwithstanding Derek’s proposed method of breaking and entering, that still takes time, effort, makes noise, etc, and thus is a deterrent).  In some cases clay, or lime plaster may not be enough, in other cases it will.  Installing a second plaster on the inside face of the bamboo framing would provide additional security (real and perceived).  
>> 
>> For the Home Expo building I suggest installing a cement plaster (with up to 50% lime if you can get your hands on it) on half the building, and a clay plaster with a durable finish on the other half.  With and without a second plaster on the interior.  Let people see how they both feel, look, and sound, and allow them to decide which would work for their circumstance.
>>  
>> Cordaid, a Dutch organization, built a prototype wood-framed house in Leogane, Haiti with no less than 7 enclosure-finish systems.  (I can send photos, if you haven't seen it already.)  I think it goes too far to the point of being chaotic/confusing.  But a couple variations in one prototype building seems valid to me.  Looking at opposite corners you might only see one finish at a time.
>> 
>> In terms of security, doors and windows (shutters?) will probably be a greater point of vulnerability than the wall enclosure system.  I would show how that can be addressed on at least one opening.  
>> 
>> Also, although security can be a serious issue in parts of Haiti (and other places in the world!), there of course is much more to consider about this building . . .
>> 
>> Martin Hammer  
>> 
>> 
>> On 2/28/11 6:15 PM, "Andrew Webb" <andrew at thegreenwebb.com> wrote:
>> 
>> > Except perhaps in perception - concrete may be less tempting to try to 
>> > break through than clay (if it is obviously clay) even if doing so is 
>> > just as easy.  The finish and the image it projects is likely a factor.
>> > 
>> > -Andrew Webb
>> > 
>> > On 1/03/2011 11:41 AM, john rehorn wrote:
>> >> Good point, Derek.  Thick clay or lime would be as good a 'vandal wall' as 
>> >> one inch of cementatious.
>> >> 
>> >> John Reho
>> >> 
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